GI problems I - Ow Flashcards
What is normocytic anaemia
Response to inflammation (reduced bone marrow activity)
May be due to bleeding as well but less of a factor
- Acute bleeding can drop Hb without change in MCV
- Chronic bleeding can drop Hb but usually MCV falls due to iron deficiency
Low albumin and high ferritin
- Acute phase reaction
Describe chrons disease
At any point of the GI tract (commonly ilium and colon)
Discontinuous (skip lesions, may spare rectum)
Can cause deep ulcers and cobblestone appearance
Transmural inflammation
- Starts as small ulcers on mucosa
- Progresses to deep penetrating ulcers with fissuring
- Mucosa swollen cobblestone appearance
Granulomas my be present but not required for diagnosis
Made worse by smoking
Different behaviours e.g. inflammatory, fistulising, structuring, perianal
Ulcerative colitis
Colon only
Continuous inflammation starting at the rectum spreads proximally
Shallow ulcers
Mucosal inflammation(diffuse and regular)
Smoking is protective
Inflammatory
No macroscopic inflammation except in severe disease
Churns disease presentation
Depends on the part of the GI tract involved and the clinical subtype
Inflammatory, structuring, fistulising, perianal
Chrons disease
- Colitis?
- ileitis?
- Gastritis / duodenitis?
- Diarrhoea, bleeding
- Abdominal pain, typically at least an hour or so post prandial
- Dyspepsia
Churns disease
- Stricturing
- Abdominal pain and distention
- Vomiting
- Bowels not opened
Chrons disease
- fistulising
Fistula is an abnormal connection/ tract between the gut and another organ / vessel
e. g. small intestine and skin
- Small intestine and small intestine
- Rectum and vagina
- Oesophagus and trachea
Chrons disease - perianal?
Perianal access
Perianal fistula
Anal fissure
UC: clinical?
Diarrhoea, bleeding Frequent bowel motions and urgency Abdominal discomfort Fever, malaise, weight loss (constitutional symptoms) Blood tests: Raised ESR/ CRP, platelets
Toxic megacolon in UC
Inflammation in the mucosa extends into the smooth muscle layer, inflammatory mediators released including nitric oxide, NO inhibitor of smooth muscle tone, arrested colonic movement leads to progressive dilatation.
Common causes of weightless in Chrons disease
Malabsorption
Chronic inflammation –> catabolism and anorexia
Pain and reduced intake
Treatment of IBD in general
5-aminosaliclyates (5-ASA) - mild anti-inflammatory action - Steroids - Immunosuppression: Azatriaprine, 6-mecaptopurine Biologics (antitumor necrosis factor) - Infliximab, adalimumab
principles of surgery in IBD
Failure of medical treatment - resect diseased bowel, colectomy, iliac resection Treatment of complications - Bowel obstruction - Perforation - Fistula - Abscess
In UC colectomy is curative, in chrons, no cure
what are the consequences of resection of terminal ilium
B12 malabsorption
Loss of specialised receptors for B12/ intrinsic factor complex
Reduced Bile salt re-uptake via enterohepatic circulation
Bile salts lost through colon / faeces
= fat malabsorption (steatorrhea)
Bile salts in colon are irritants, stimulate water and electrolyte secretion –> secretory diarrhoea
types of rectal bleeding and their presentations
Upper GI: melaena
Lower GI:
Dark rectal bleeding mixed with stools = proximal colon (caecum - transverse, distal small intestine)
Bright red mixed with stools
= left colon
Outlet (haemorrhoids / fissure): usually fresh and on paper, docent usually cause iron deficiency
Do you bleed in coeliac disease?
Not usually
Thinking about iron definicy anaemia: things to consider
Age and gender:
- Young women without GI symptoms: likely menstrual loss
- Young women with GI symptoms: often needs investigating
- Older women (especially post menopausal) and in all men: always needs investigating
Break it down to:
inadequate dietary intake - vegetarian
Impaired absorption - coeliac disease
Abnormal loss - adverse and occult bleeding e.g. inflammation, ulcers, diverticulitis, cancer, polyps, angiodsyplasia
What are the investigative iron studies you can perform?
Serum iron
Iron binding capacity / transferrin
Iron saturation
Ferritin
The common differentials to consider with GI problems
Infection Coeliac disease IBS IBD Cancer
Coeliac serology
First look for coeliac disease
- Needs to be done whilst consuming gluten
IgA tissue transglutamase antibodies
- Preferred
- As these are IgA antibodies result can be falsely negative in people with IgA deficiency
Other antibodies that can be measured
- Disseminated gliadin peptide antibodies
- Endomysial antibodies
Endoscopy and duodenal biopsy
Histological diagnosis still considered gold standard
Varying severity of histological changes
Biopsies taken from proximal duodenum
Genetics
> 99% of patients with coeliac disease carry either HLA-DQ2 or HLA-DQ8, but these are also present in at least 50% of the general population
SO if positive doesnt help you in diagnosing coeliac disease (because is present in so many other healthy individuals)
But if negative makes coeliac disease extremely unlikely
Association with coeliac disease
Dermatitis herpertiformis First degree relative with coeliac disease Type 1 diabetes Autoimmune thyroid disease Osteoporosis Infertility / recurrent miscarriage Unexplained neurological disease addison disease Sjogrens syndrome Down and turner syndromes primary biliary cirrhosis
Treatment
Gluten free diet main sources of gluten - Wheat - Barley - Rye Oats - Tiny proportion of coeliacs cannot tolerate - Beware of cross contamination with wheat
